Historically, systems have been developed to provide reading material based on raised dots that can be used by a blind or visually impaired person to obtain information, such as the Braille system that provides letters and numerals coded in the raised dots. Thus text originally composed in a visual manner, such as ordinary text using the English alphabet, is translated into the Braille system, so that the original English text can be understood by a visually impaired person. Traditionally, the raised dots are produced on a strip or page of paper by mechanical means, such as mechanical levers or other mechanisms that form impressions on the paper. Mechanical devices, such as a braille writer, have been developed that an operator can use to impress or, in effect, type the raised dots on the paper. Computer systems have been developed to allow an operator to type the characters into a computer, which are then converted into Braille, and a computer system mechanically produces the Braille text or produces printing plates or masters that can be used in printing Braille books or documents.
Modern systems have also been developed to display Braille and other information on a raised-dot display. Such a system uses some technique such as a mechanical approach to raise a dot (or bump) above a flat surface. The raised bumps form a Braille message or provide other information such as a graphic information. Various approaches for displays for visually impaired individuals have been developed or considered. These conventional approaches include shape memory alloys (SMA), electro-rheological fluids, solenoids, piezoelectric approaches, rotating disks, microfluidic valves, electroactive polymers, microstep motors, electrothermic actuators, electromagnetic microresonators, pneumatic microvalues, low melting point metal actuators, and RC (radio controlled) servomotors.